GIS-FA: an approach to integrating thematic maps, factor-analytic, and envirotyping for cultivar targeting.

KEY MESSAGE: We propose an "enviromics" prediction model for recommending cultivars based on thematic maps aimed at decision-makers. Parsimonious methods that capture genotype-by-environment interaction (GEI) in multi-environment trials (MET) are important in breeding programs. Understanding the causes and factors of GEI allows the utilization of genotype adaptations in the target population of environments through environmental features and factor-analytic (FA) models. Here, we present a novel predictive breeding approach called GIS-FA, which integrates geographic information systems (GIS) techniques, FA models, partial least squares (PLS) regression, and enviromics to predict phenotypic performance in untested environments. The GIS-FA approach enables: (i) the prediction of the phenotypic performance of tested genotypes in untested environments, (ii) the selection of the best-ranking genotypes based on their overall performance and stability using the FA selection tools, and (iii) the creation of thematic maps showing overall or pairwise performance and stability for decision-making. We exemplify the usage of the GIS-FA approach using two datasets of rice [Oryza sativa (L.)] and soybean [Glycine max (L.) Merr.] in MET spread over tropical areas. In summary, our novel predictive method allows the identification of new breeding scenarios by pinpointing groups of environments where genotypes demonstrate superior predicted performance. It also facilitates and optimizes cultivar recommendations by utilizing thematic maps.

Design of an interferometric fiber optic parametric amplifier for the rejection of unwanted four-wave mixing products.

We introduce a novel (to our knolwedge) interferometric fiber optic parametric amplifier (FOPA), allowing for the suppression of unwanted four-wave mixing products. We perform simulations of two configurations where one rejects idlers and, the other rejects nonlinear crosstalk from the signal output port. The numerical simulations presented here demonstrate the practical feasibility of suppressing idlers by >28 dB across at least 10 THz enabling the reuse of the idler frequencies for signal amplification and thus doubling the employable FOPA gain bandwidth. We demonstrate it can be achieved even when the interferometer employs real-world couplers by introducing a small attenuation in one of the interferometer arms.

Design and transmission analysis of trench-assisted multi-core fibre in standard cladding diameter.

6-core and 8-core trench-assisted heterogeneous fibres in standard cladding diameter are designed using artificial intelligence-based techniques including a cut-off wavelength regressor. The designs proposed here, for the first time, suppress crosstalk at 1550 nm of 8-core fibre to as low as -55 dB/km covering the whole S+C+L band while keeping coating loss below 0.001 dB/km. We compare them to reveal the influence of the additional cores in the 125 µm cladding diameter scenario. We report on the transmission characteristics and performance of the MCFs in terms of capacity and spatial spectral efficiency, including the influence of bandwidth, effective mode area, distance and crosstalk, for a range of transmission distances. The artificial intelligence-based method and insights given can be used to significantly speed up and tailor designs for a variety of telecom and datacom applications.

Overcoming degradation in spatial multiplexing systems with stochastic nonlinear impairments.

Single-mode optical fibres now underpin telecommunication systems and have allowed continuous increases in traffic volume and bandwidth demand whilst simultaneously reducing cost- and energy-per-bit over the last 40 years. However, it is now recognised that such systems are rapidly approaching the limits imposed by the nonlinear Kerr effect. To address this, recent research has been carried out into mitigating Kerr nonlinearities to increase the nonlinear threshold and into spatial multiplexing to offer additional spatial pathways. However, given the complexity associated with nonlinear transmission in spatial multiplexed systems subject to random inter-spatial-path nonlinearities it is widely believed that these technologies are mutually exclusive. By investigating the linear and nonlinear crosstalk in few-mode fibres based optical communications, we numerically demonstrate, for the first time, that even in the presence of significant random mixing of signals, substantial performance benefits are possible. To achieve this, the impact of linear mixing on the Kerr nonlinearities should be taken into account using different compensation strategies for different linear mixing regimes. For the optical communication systems studied, we demonstrate that the performance may be more than doubled with the appropriate selection of compensation method for fibre characteristics which match those presented in the literature.